Dual purpose unrefined/refined petroleum intermodal tank container

ABSTRACT

A dual-purpose tank container is provided, designed for transporting unrefined or refined petroleum, together with a transportation process optimized to utilize available weight limits of transportation means and eliminate unproductive deadheading. The tank container includes inner tank and outer insulation shell, the inner tank being equipped with one or two diaphragms so that a fluid, for example crude oil or gasoline, can fully occupy inner space without risk of contamination from a residual fluid.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is continuation of provisional U.S. patent application Ser. No. 62/647,629 filled on Mar. 24, 2018, incorporated herein by reference. A reply notice received May 5, 2018, Nr. OC000000098934860

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT (If APPLICABLE)

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX (IF APPLICABLE)

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ABSTRACT OF THE DISCLOSURE

A dual-purpose tank container is provided, designed for transporting unrefined or refined petroleum, together with a transportation process optimized to utilize available weight limits of transportation means and eliminate unproductive deadheading.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to a commodity carrier and the encompassing logistic transportation system. More particularly it relates to an intermodal tank container type carrier adapted to transfer any number of loadings of two different liquids without subjecting either liquid to contamination by residue of the other. The logistic transportation system consists of proprietary intermodal containerized fluid transfer pump used for loading at the primary fluid source, standard intermodal container ground transport via roads, railway or sea, and similar fluid transfer pump used for unloading primary fluid at the destination and consequently loading secondary fluid while avoiding cross contamination.

Description of Related Art

Pipelines are thought to be the most economical way how to transfer petroleum from its raw source, crude oil producer, to a refinery for refining and production of petroleum distillates, and finally to the final customer. Since they are stationary, they require various additional transport services, for example first or last mile trucking in and out of pipeline storage facilities, or rail and sea transport with additional infrastructure needed for loading and unloading of cargo. The related additional costs are not always obvious, and are known to the one skilled in the art. The petroleum transfer logistic includes many cases of deadheading, when there is no cargo transported on the return trip of the cargo transporter. The proposed dual-purpose intermodal tank container would at least partially improve the economics of the unrefined/refined petroleum transport.

Since the tank container is intermodal, it has standard structural dimensions. Such a tank container is possible to transport from a cargo loading source to the designed destination continuously using standardized cargo transporters via road, rail or marine, without need for building expensive petroleum transfer infrastructure.

The economics of a such logistic solution would excel in an environment, where is substantial price differential between two commodities. For example, in Western Canada, there is a difference between price of unrefined and refined petroleum products in compare to US gulf coast where the same price difference is transposed.

It makes economic sense, to load a load of crude oil as close as possible to a production source in Canada, transport the load to a refinery in the US Gulf Coast, and return back to Canada with a load of gasoline or other petroleum refined product.

Such logistic solution is very well competitive with pipeline or rail petroleum transport. It is believed that pipeline is on average 20 percent less expensive than rail especially in case of longer routes (Kyle Bakx, 2017). But pipeline streams a product only one way. Additionally, in case of heavy crude oil and bitumen, which is majority petroleum product in Western Canada, there is need for a thinning agent, such as diluent, which conditions the crude oil for pipeline transport. This need adds on average 30 percent of volume to the transported crude oil (Spackman, 2016). There are also costs related to other conditioning of the crude oil before it can be transported via pipelines. Good example is removal of solids and water content below 0.5 percent of the volume. Rail transport is not so stringent in requirements for water and solid content of the transported crude oil. After factoring in all possible costs, the rail transport can be cost competitive with pipeline or can be even more economic in some cases. Although rail transport can also benefit from utilization of return trip, it still needs transfer stations which are expensive to build and maintain. It also utilizes designed railway cars with inherent safety flaws.

The proposed intermodal logistic solution is designed to be superior to both above mentioned transport modes. It eliminates most of the cost related to cargo transfer between modes whenever it is necessary. In the best case, the unrefined petroleum is loaded at the oilfield using own designed intermodal containerized pump into the intermodal tank container. The crude oil producer is not required to build any additional infrastructure, just provide access to the right riser outlet at the crude oil source tank farm or flowline. The fluid is loaded only once right at the source and unloaded at the final destination at the refinery using similar model of intermodal pumps located therein. This is the most important point of the proposed logistic solution, and the scope of its effects is obvious to those skilled in the art.

Majority of the larger oil producers have pipeline access at their oilfield. They need to set up processing facilities for conditioning of produced crude oil before it is pipelined via small local pipelines to the major pipeline terminals. Sometime they get restricted on available volume for transfer, thus implying need for road trucking of the extra produced crude oil to the nearest transfer terminal. It all adds to the cost. The proposed logistic solution can accept crude oil right at the source oil well leases, after moderate conditioning. Thus, bypassing all the flowlines and processing facilities.

After loading crude oil, the intermodal tank container is trucked to the nearest railway depot where it is quickly transferred using standard container handlers, either mobile or stationary, onto a railway well car. A suitable five-unit articulated double stack well car is best choice for a such transport since the deadweight including the container tare weight is comparable to a standard railway tank car tare weight. After the train is loaded it travels to a refinery where the tank containers get unloaded and optionally subsequently or simultaneously loaded with refined products. It would be also possible to transload the tank containers onto suitable container steamship, equipped with an unloading mechanism similar to the designed container pump. Such transport design would allow unloading of cargo at a refinery river or sea berth, which is a standard part of river or seaside refineries. The refined products, loaded into secondary compartment of the container tank, can travel all the way back to the starting point of the trip, or be unloaded at a suitable destination, and the container returns to the starting point empty.

In order to carry two distinct fluids without risk of cross contamination, the intermodal tank container must be appropriately designed. The prior art solutions go as far as 1949 when Standard Oil Co invented multiple compartment tank, U.S. Pat. No. 2,758,747A. With advance in computerized machining and flexible material manufacturing, it is possible to improve the invention in the following way.

First, using standard intermodal ISO container sizing design tank container which can be transported in different modes without additional requirements. The design respects weight restrictions, primarily for road transportation, which complete scope is known to those skilled in the art.

Next requirement is to design the tank dividing diaphragm in the vessel intersecting the tank vertically in the middle in case of one diaphragm or anywhere else in case of multiple diaphragms. The diaphragm copies half of the tank shape and can turn inside out into other side of the tank when pressured by gas or liquid. The tank halves are both designed for different use. Compartment one is for unrefined petroleum, compartment two is for refined petroleum. Unrefined petroleum can be very viscous, for example, neat bitumen hardly flows in ambient temperatures. Therefore, the compartment one could be optionally equipped with heating mechanism in the form of electric heating cables applied on the interior bottom of the tank compartment one and on the bottom part of the diaphragm on the same side. There is also option of a container tank without heating elements, thus requiring some minimal dilution of the unrefined petroleum. The tank has insulation layer within the space between exterior and second shell formed from light composite material. The diaphragm is also equipped with heat reflection layer on the compartment two side. This is necessary for faster cooling before the compartment two is filled up with refined petroleum, which is usually volatile. When compartment one, containing viscous crude oil, is being emptied, the diaphragm propagate pressure from injected gas or liquid pressured into the compartment two, thus pushing on the viscous fluid and accelerating the unrefined petroleum unloading process.

In order to allow the emptied part to be almost completely drained of liquids, the diaphragm has special patterned surface which forms draining fluid channels even if fully pressed against tank internal wall. This solution is inspired by U.S. Pat. No. 5,027,860A. The compartment one diaphragm surface pattern is more robust since the unrefined crude oil is viscous and requires wider drain channels. Each half of the tank has a loading/unloading single inlet/outlet on the bottom. Each half is also equipped with a single vapor injection/suction inlet/outlet on top of the tank. Tank halves are further equipped with pressure relief valve and excessive vacuum breaker valve.

The logistic system is designed to exert minimal implementation cost on its customers. In order to achieve such objective, it needs an element which supply fluids transfer function. This is achieved using intermodal containerized pump for fluid loading or unloading to and from the intermodal tank container. As the pump container is itself intermodal, it can be easily transferred using the same means as the intermodal tank container. The intermodal pump container consists of two pumps, each can supply loading and unloading function according to a situation. There is also appropriate sized nitrogen generator installed to supply sufficient flow of nitrogen gas or liquid needed for cooling or preparation of inert environment inside the container tank. The pumps inside the intermodal container, are both equipped with a flexible hose which, at best, automatically connect to the close sidewise positioned intermodal tank container inlet valve. This connection process can be achieved using a telescopic bridge automatically governed from the inside of the pump container. Once the fluid flow channel is established, the fluid transfer process can begin. At best, the unloaded fluid present in the first tank compartment being unloaded by the first pump is pushed against the outlet on the bottom of the tank with help of the diaphragm, which is itself being pushed by the incoming fluid loaded into the second tank compartment by the second pump. Such push effect can be also achieved by a generated gas released into the second compartment. Using both pumping actions simultaneously is optional, but desired as it represents significant time savings as it allows unload and load tank container at the same time. Naturally, also an empty container can be simply filled up with the incoming fluid while the vapor suction outlet removes present gases which would otherwise compress and prevent proper filling of the tank. At the loading/unloading location, pump is simply connected to a dedicated fluid riser(s) which provide channel for ingoing or outgoing fluid(s). The whole system transfers petroleum fluids in very small batches, and as such each one can be chemically customized or diluted according to composition of the fluid and/or requirements of the final customer.

BRIEF SUMMARY OF THE INVENTION

In today's world, speed and modularity dominate the global transportation system. The presented invention implements such system properties in petroleum transport logistic. Using dual purpose intermodal tank container, it can facilitate unrefined petroleum transport from oilfield to a destination refinery via various combined modes of transport. In order to maximize economic benefits from transporting cargo both ways, the dual-purpose intermodal tank container can be loaded at a destination refinery with refined petroleum and delivers such cargo to customers on the way back to an oilfield.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is an example of cross sectional side elevation of an embodiment of an intermodal tank container of this invention, to provide context.

FIG. 2 is a schematic flow diagram showing ideal transport process of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, there are two designs of the intermodal container tank considered. Small version which is 20 feet long (TEU), 8 feet wide, 8.5 feet high, and large version 40 feet long (FEU), 8 feet wide and 8.5 feet high. TEU has cargo weight capacity approx. 24 tones, FEU approx. 45 tones. FEU weight is non-standard for a similar container of such size, but it is still within limits for Canadian road transport, which is 63 tones for a truck GVW (Gross Vehicle Weight) (Alberta, 2018). In most of US states the road GVW weight limit is 80000 Lbs. (Transportation, 2003), which technically prevents road movements of FEU container tanks within US. Although is FEU nonstandard and overweight, it is still within the limits of mainstream heavy duty standard container yard lifting equipment. TEU intermodal tank has two compartments divided by a single diaphragm. FEU has three compartments, divided by two diaphragms. The two diaphragms form one middle and two divided compartments at each end. The volumes of the middle and the two side compartments together are equal when filled up, thanks to the plasticity of the dividing diaphragms. The side compartments are designed for unrefined petroleum, where the diaphragms provide secondary containment measure in case of the tank wall breach (dividing the tank volume of 300 barrels into 2×150 barrels). Middle compartment is designed for refined petroleum. All three compartments have their own excessive vacuum breaker valves and overpressure control valves together with dedicated manhole. They are also equipped with pressure and tank level sensors. Referring to FIG. 2, the steps expected in the use of the intermodal tank container designed for transportation of unrefined/refined petroleum fluid include:

-   -   1. Unrefined petroleum, preferably in high temperature and low         viscosity, is transferred from a storage tank to the intermodal         insulated pressurized tank container using either standard oil         pump or specially designed loading pump. While loading it is         possible to inject chemicals and diluents to adjust the         petroleum properties to the desired level.     -   2. The container tank is transported from the loading station,         to an intermodal rail yard, using standard truck trailer         chassis.     -   3. At the intermodal rail yard, the container tank is         transferred from truck chassis to a railway flat car, preferably         a multiunit double stack well car, using standard lifting and         stacking equipment.     -   4. A train transport container tanks to an intermodal sea port,         where are the container tanks transferred onto a container         steamship equipped with unloading pumps.     -   5. Because most of world's refineries is located near waterways,         the container steamship travels from the sea port to a refinery         berth.     -   6. At a refinery berth, steamship unloading pumps unload the         unrefined petroleum and load refined petroleum into the         container tanks secondary compartment.     -   7. Steamship departs refinery berth and arrives back at the         intermodal seaport.     -   8. The container tanks are unloaded from steamship onto a train         well cars and transported to the unrefined petroleum production         source.     -   9. The refined petroleum cargo is optionally unloaded along the         way or is utilized at the petroleum production source as a         diluent.

The above steps can be reduced to simpler transporting of container tanks using train from a loading source to a refinery and back without utilizing seaways.

Viscous bitumen, produced in the Canadian province Alberta, as an example of unrefined petroleum, carries a significant market price discount. There are two factors forming this discount, qualitative and geolocational. The bitumen is very heavy and sour crude with 4% sulfur content and 20% volume of asphaltenes (Strautz, 1977). It had been easier to refine lighter crude oil grades until advent of more complicated refining processes such as coking and hydrotreating. For such complex refineries, extra heavy crudes represent so called opportunity crudes, which are harder to refine, but yield more product volume especially when natural gas price is low. The heavy crude oil transportation also represents a challenge since the oil must be diluted in order to be accepted into pipeline transport.

The presented invention solves some of these problems. The transported heavy crude oil doesn't need to be diluted to usual 3:7 ratio (diluent: crude oil), it just needs to attain certain lower viscosity so it can be unloaded from the container using the diaphragm pressurized from the second compartment. A specialized pump, which utilizes electronic flow sensors, registers pumped crude oil composition and adjusts the injection of the chemicals accordingly. The crude oil cargo travels from source to a refinery usually quite few days. This time can be utilized for preconditioning of the crude oil according to the refinery needs. The container tank can be also equipped with optional tray on the bottom. This tray represents about 2.5% of the tank volume and is designed for aggregation of unwanted precipitate, which would stay there until the container tank returns to the point of origin. The tray is then washed out according to sediment level, using the loading pump system and a solvent.

There is enormous advantage hidden in a such system. The content of every batch represented by every single container tank, with capacity approx. 300 barrels, is described using above mentioned sensors in the loading pump flow lines, and thus there is possibility to construct a specific crude oil essay for every set of these batches. The container tanks are not limited just for heavy oil, they can be utilized for light oil as well as various condensates. It is possible to prepare complete refinery blends which can be blended in fly while being unloaded from a sea vessel directly into refinery charging tanks. Such designed system would skip many problematic refinery segments and crude oil blends preparation steps, such as dewatering, desalting, blending and chemical preconditioning.

The geolocational factor of the discount represents transportation costs. The production source of the Canadian bitumen is landlocked in the province of Alberta. The pipeline capacity has its limits, and crude oil producers and transporting companies are eager to find ways how to get the oil to the tidewaters. The other economically acceptable option, beside pipelines, is railway transport. Conventional tank car trains require loading and unloading stations, which are costly to build and maintain. While containerized oil transportation can be merged into existing flow of general cargo containers. It is a fact known to the ones skilled in the art, that container slots in intermodal trains are underutilized. In average, railway well cars are loaded to about 50% of their weight capacity (Pickel, 2015). The intermodal railway transportation is a special example of underutilization since, in North America, there is uneven flow of full containers from west to east coast and flow of empty containers the other way. In average 100 car train, there are always at least two locomotives, a rule independent of the train weight requirements. Higher tonnage per car would represent just some percentage higher fuel cost, since all other capital costs, equipment, manpower etc., are fixed per train. A five-well intermodal double stack flat car can carry ten containers. Allowed tonnage per each of the middle wells is about 55 tones and 70 tones at each end well. Such average multi-well railway car can carry, for example, four FEU tanks with bitumen weighting 50 tones, two FEU with general cargo 2×25 tones, another two empty FEUs 2×5 tones, and two 53 domestic reefers weighting 20 tones each. In this configuration, the rail car tonnage capacity would be almost fully utilized.

The same utilization problem exists in marine container transport. Just the costs are the same for both ways, since a steamship burns fuel hauling ballast water when traveling underutilized. Good example would be transport of bitumen from Alberta to Californian west coast refineries. The container is loaded at a production oil field in Athabasca region and travels on a truck trailer chassis to the nearest intermodal container yard near Fort McMurray. There the container is merged with other tank containers on an intermodal double stack train, travels to Edmonton to an intermodal container yard, is mixed with general cargo intermodal containers and is shipped to Vancouver. There is loaded onto a special RoRo (roll on roll off) steamship, which has container tank slots on the bottom under deck equipped with pumps. The RoRo steamship can also load general cargo containers above deck. With full container tanks of bitumen on the bottom, there would be still enough tonnage capacity to load above deck slots with empty general cargo containers. The steamship would travel to a California coast refinery, unload bitumen at a berth and load gasoline or any other refined products. The ship would stop at Long Beach seaport, unload empty general cargo containers located above deck, load full ones and travel back to Washington/B.C. coast. The refined products could be unloaded along the way at any suitable port or terminal. The full general cargo containers can be transferred at the same port as the empty tank containers onto an intermodal train and travel to Edmonton to an intermodal yard.

The primary goal of the whole logistic system is utilization of tonnage capacity and elimination of deadheading.

In the preceding description, for purposes of explanation, numerous details are mentioned in order to provide sufficient understanding of the embodiments of the invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the invention.

The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations can be affected to the particular embodiments by those skilled in the art without departing from the scope of the invention, which is defined solely by 

1. Intermodal pressurized insulated tank container adapted to accommodate loading or unloading- of unrefined and refined liquids at same or separate times, comprising of at least two compartments separated by flexible and formidable diaphragm, while avoiding fluid cross contamination.
 2. Logistic process of unrefined/refined petroleum transport by a dual-purpose intermodal tank container, set forth in claim 1, comprising the steps of: a) Loading unrefined petroleum of sufficiently low viscosity into insulated intermodal tank container; b) Transporting the intermodal tank container using a road truck trailer chassis from petroleum production source to a railway container yard; c) Transporting the intermodal tank container using a standard intermodal train to a seaport; d) Loading the tank container onto a container steamship equipped with pumps; e) Transporting the loaded steamship to a refinery berth; f) Unloading the unrefined cargo and simultaneously loading a refined petroleum into secondary compartment of the dual-purpose container tanks; g) Transporting the refined petroleum by steamship to another destination; and h) Unloading the refined petroleum from the container tanks.
 3. The process of claim 2, but with the steps in the order f, g, h, a, b, c, d, e.
 4. Multipurpose Ro-ro ship, as mentioned in claim 2, with specialized plumbing, pumping and blending equipment, capable of unloading or loading of multiple intermodal tank containers, set forth in claim 1, while reaching desired unrefined/refined petroleum properties of the final blend.
 5. Multipurpose Ro-ro ship, as set forth in claim 4, but solely or additionally equipped with specialized plumbing, pumping and blending equipment adapted for handling of subzero cryogenic liquids, capable of unloading of multiple specialized intermodal tank containers, loaded with liquefied natural gas (LNG) or liquefied petroleum gas (LPG), while reaching desired properties of the final natural gas blend. 